Chapter 1 Recovered Paper and the U.S. Solid Waste Dilemma I 1 by Rodney Young Introduction and Overview ...... 1 Paper Industry Response to the Solid Waste Issue ...... 2 U.S. Recovered Paper Consumption ...... 2 U.S. Trade in Recovered Paper ...... 3 U.S. Recovered Paper Recovery ...... 3 Recovered Paper Supply and Cost ...... 3 Bibliography ...... 4 Resources ...... 4

Chapter 2 Recycled- Versus Virgin-Fiber Characteristics: A Comparison 1 7 by R. L. Ellls and K. M. Ssdlachsk Introduction ...... 7 Literature Review ...... 8 General Effect of Recycling ...... 8 Effect of Furnish ...... 10 Effect of initial Beating of Virgin Pulp ...... 10 Theory for Tensile Strength of Paper ...... 10 First Assumption ...... 11 Second Assumption ...... 12 Theory Verification ...... 12 lnleractions Between Fiber Properties and Process Variables ...... 14 Reformulation of the Page Equation ...... 15 Approach ...... 15 Results and Discussion ...... 16 Fiber Strength ...... 16 CoarsenessiPerimeter ...... 16 Freeness Change of Recycled Fibers ...... 18 Conclusions ...... 19 Bibliography ...... 19 Literature Cited ...... 19

vii Chapter 3 Print Quality of Recycled-Fiber Papers: A Review 1 21 by Joseph S. Aspler Introduction ...... 21 Changes in Fiber Properties and Their Influence on Sheet Slructure ...... 21 Changes in Printing Properties ...... 22 Newsprint and Mechanical Grades ...... 22 Coated and Wood-Free Grades ...... 23 Fines and Ink Holdout ...... 23 Optical Properties ...... 24 Linting and Picking ...... 24 Water Absorbency of Recycled-Fikr Paper ...... 25 Dimensional Stability ...... 25 Web Breaks ...... 25 Summary and Conclusions ...... 26 Acknowledgements ...... 26 Bibliography ...... 26 Literature Cited ...... 26

Chapter 4 The Impact of Secondary Fiber on the Paper Machine 1 29 by Wllllarn E. Srnlth and Unds Brooks Bunker Introduction ...... 29 Machine Runnability ...... 29 Buildup of Suspended Solid? ...... 29 Suspended Particulate Materials ...... 30 Microbiological Deposits ...... 32 Buildup of Dissolved Solid? ...... 32 Fikr Fragments and Suspended Wood Tissue ...... 33 Sheet Properties ...... 34 Residual Contamination ...... 34 Effects of Dried Fibers and Higher Fines Content ...... 35 Bibliography ...... 36 Resources ...... 36

Chapter 5 Fiber Reactivity Versus Chemical Use I 37

Introduction ...... 37 Background ...... 37 Discussion ...... 38 The Handling of Noncellulosic Particulate Materials from Waste ...... 38 Potential Problems Relating to Those Chemicals Coming with Waste Fibers ...... 38 Carry-Over hom the Preparation of Recycled Fibers ...... 39 The Use of Strength Additives. Sizing Agents. and Retention Aids in Furnishes Containing Large Amounts of Recycled Fiber ...... 39 Conclusions ...... 40 Bibliography ...... 40 Literature Cited ...... 40

viii Chapter 6 Characterization of Wastes and Emlssions from Mills Using Recovered Fiber 1 41 by Reld Miner. Arun Someshwar. Paul Wlepnd. Robert Flsher. Herbert Berger. Dennis Baton. and Jay Unwln Introduction ...... 41 Wastewater Characteristics ...... 41 Wastewater Loads ...... 41 Wastewater Treatment Technologies ...... 47 Specific Chemical Constitueds of Wastewaters ...... 48 PCBs in Wastewaters ...... 48 Bioassay Responses ...... 50 AirEmissions ...... 55 Repulping and Deinking Operations ...... 55 Bleaching Operations ...... 56 Manufacture of Paper and Board ...... 56 Volatilization in the Waste Treatment System ...... 56 Burning of Recovered-fiber Wastes and Fossil Fuels ...... 58 Solid Wastes from Recovered-fiber Paper Mills ...... 60 The Origin of Solid Wastes ...... 60 Pulper ...... 60 Contaminant Removal Prior to Deinking ...... 60 Deinking ...... 60 Contaminant Removal Afier Deinking ...... 60 Factors That Influence Solid-waste Characteristics ...... 60 Quantities of Solid Waste Produced ...... 61 Sludge Dewatering ...... 62 Physical Propeflies of Recovered-fiber Sludge ...... 62 AshConlent ...... 62 Other Physical Properties ...... 64 Chemical Properties of Recovered-fiber Sludge ...... 64 Constituents of Sludge Extracts ...... 65 PCBs in Deinking Sludges ...... 65 Sludge Disposal Alternatives ...... 65 Current Practices ...... 65 Research into Alternative Disposal Methods ...... 65 Summary ...... 65 Bibliography ...... 67

Chapter 7 Nonpaper Uses for Recovered Paper 1 69 by Thomas Frlberg Scope and Opportunity ...... 69 Description of Raw Materials ...... 69 Products ...... 70 LooseFiber ...... 70 Fuel ...... 70 Insulation ...... 70 MoldedPulp ...... 72 Animal Bedding ...... 72 Fillers ...... 72 Bonded Systems (Composites) ...... 73 Chemical Derivatives ...... 73 Processes ...... 73 Collection ...... 73 Soding ...... 73 Wet Processing ...... 73 Dry Processing ...... 73 Chemical Processing ...... 73 . . Recyclabll~ty ...... 73 Economic Considerations ...... 74 Summary ...... 74 Bibliography ...... 74

Chapter 8 Sourcing and Grading of Secondary Fiber / 75 by Danlel 8. Mulllgan Introduction ...... 75 Considerations ...... 75 EPA Guidelines ...... 76 Sourcing ...... 76 Grading ...... 77 Bibliography ...... 78

Chapter 9 Recovered Paper Contaminants / 79 by Barbara M. Balos and James V. Patterson Introduction ...... 79 Paper Additives Become Potential Contaminants ...... 79 Relationships Between Products from Secondary Fiber and Their Original Paper Sources ...... 79 Review of Major Cornaminants. Resulting Problems. and Methods of Removal ...... 81 Fillers. Clays. Titanium Dioxide. Calcium Carbonate. and Talc ...... 81 Rosin. Alum. NaturaI Resins. and Wax Sizes ...... 81 Starches and Gums ...... 81 Dyes and Pigments ...... 82 Inks ...... 82 Hot.Melts. Plastic Coatings. and Asphalts ...... 82 Loose Plastic. Styrofoam. and Treated Tapes ...... 82 Heavy Materials ...... 82 Conclusion ...... 82 Bibliography ...... 82

Chapter 10 Introduction to Secondary-Fiber Processing / 85 by Richard J. Spangenberg Chapter 11 Receiving. Inspection. and Storage of Secondary Fiber 1 87 by Bob Mlller . . Rece~v~ng 87 Transportation ...... 87 Unloading and Handling Equipment ...... 88 lnspction ...... 88 Sorting ...... 88 Material Specifications ...... 88 Storage ...... 88 Bibliography ...... 89

Chapter 12 Pulping of Secondary Fiber 1 91 by F. Cllnt Cleveland Introduction ...... 91 Pulping of Secondary Fiber ...... 91 Pulper Feed Conveyor ...... 91 Pulper Feeding Control ...... 93 Pulping Variables ...... 94 Chemicals ...... 95 Causlic (Sodium Hydroxide) ...... 95 Hydrogen Peroxide ...... 95 Hydrosulfite/FormamidineSulfinic Acid(FAS) ...... 95 Sodium Silicate ...... 95 Chelant ...... 95 Collector ...... 95 Anionic ...... 95 Cationic ...... 95 Ampholitic ...... 95 Nonionic ...... 95 Disprsanl ...... 95 Displectors ...... 96 Equipment Operation ...... 96 Process ConsiderationDesign Points ...... 96 PulperTypes ...... 97 PulpingInnovations ...... 99 Conclusion ...... 100 Bibliography ...... 100 Chapter 13 Cleanlng tor Contaminant Removal in Recycled-Fiber Systems 1 101 by Kevln Merriman Introduction ...... 101 Forward Cleaners ...... 103 Theory ...... 103 Forward Cleaner Design ...... 105 Chamber Diameter ...... 105 Chamber Length ...... 106 ConeAngle ...... 106 Vortex Finder Length ...... 106 Feed Orifice Diameter ...... 106 AwpsOrifice Diameter ...... 106 Rejects Orifice Diameter ...... 106 Controlled Turbulence ...... 106 Construction Materials ...... 106 Canister Configurations ...... 108 Forward Cleaner Operating Parameters ...... 108 Feed Consistency ...... 108 Operating Presures ...... 109 System Temperature ...... 109 Stock Freeness ...... 109 Reject Rate ...... 110 Control of Operating Parameters ...... 111 System Design and Cleaner Selection ...... 111 Elutriation and Fiber Recovery ...... 113 Coarse Cleaning ...... 115 Lightweight Cleaners ...... 116 Reverse Cleaners ...... 117 Through-Flow Cleaners ...... 118 Design and Operating Considerations for Hydrocyclone-Type Lighhveight Cleaners ...... 119 The Gyroclean ...... 119 Comparison of Lightweight Cleaners ...... 122 Core-Bleedcleaners ...... 122 Bibliography ...... 122

Chapter 14 Screening I 125 by Terry Bllaa Introduction ...... 125 Debris in Secondary Fiber ...... 125 Debris Size. Shape. and Orientation ...... 125 Pressure Screen Principles ...... 126 Mechanism of Debris Removal in Pressure Screens ...... 128 Positive Size Separation ...... 128 Debris Orientation ...... 128 Other Debris Removal Mechanisms ...... 129 Pressure-Screen Cylinders ...... 129 Holes 129 Slots 129 Turbulence-Generating Screen Cylinder Designs ...... 130 Measuring Screen Performance ...... 131 Debris Rejection ...... 131 Rejection of Long Fibers ...... 132 Determining Debris Content ...... 132 Pressure Screen Applications in Secondary-Fiber Systems ...... 133 Controlling Pressure Screens ...... 133 Secondary Pulpers ...... 134 Rejects Screens ...... : ...... 134 Vibrating Screens ...... 134 Batch Rejed Screens ...... 135 Modern Continuous Reject Screens ...... 136 Screeningsystem Design Considerations ...... 136 Avoid the Disintegration of Debris ...... 138 Series Screening ...... 138 Match Tailing Efficiency to the Efficiency of the Main Stream ...... 138 Practice Good Housekeeping and Maintenance ...... 138 Strive for Stable Operation ...... 138 Summary ...... 138 Bibliography ...... 139 Literature Cited ...... 139

Chapter 15 Flotatlon Deinking / 141 by Mlchael A. McCwl Introduction ...... 141 Flotation Deinking Market ...... 141 Flotation Theory ...... 141 Flotation Chemistry ...... 142 Deinking Chemicals ...... 143 Soaps ...... 143 Synthetic Collectors ...... 144 Flotation Cells ...... 144 History of Flotation Deinking Cells ...... 144 Modern Flotation Deinking Cells ...... 145 Beloit PDM Flotation Cell ...... 147 Bird-Escher Wyss CF/CFS/CFC Cells ...... 147 Black Clawson IHI/BC Flotation Cell ...... 150 Lamort DA Verticel ...... 151 Kamyr GSC Flotation Device ...... 152 Voith Multi-Injector Elliptical Cells ...... 152 Other Flotation Cells ...... 153 Flotation Deinking Systems ...... 153 Flotation Only Systems ...... 153 Combination Systems ...... 154 Single-Loop Combination Systems ...... 154 no-Loop Combination System ...... 154 Acid Loop Systems ...... 154 Post Flotation Loop ...... 155 WashingLoop ...... 156 Soaking Stage ...... 156 Three-Loop Combination System ...... 157 Measurement of Flotation Efficiency ...... 157 Brightness ...... 157 Ink Removal ...... 159 Stickies Removal ...... 159 Rejects Rate ...... 159 Deinking Efficiencies ...... 159 Quality of Deinked Pulp ...... 160 Conclusions ...... 160 Bibliography ...... 161 Literature Cited ...... 161

Chapter 16 Washing 1 163 by R.G. Horswk updated by Wllllam Forester Introduction ...... 163 Washing ...... 163 Froth Flotation ...... 163 Other Mechanical Devices ...... 163 Thickening vs. Dilution Washing ...... 163 Theory of Countercurrent Dilution Washing ...... 163 Hot-Loop System Design ...... 165 Effect of Particle Size and lnk Dispersion ...... 166 Operating Characteristics of Washers ...... 169 Low-Consistency Washers ...... 169 Sidehill Screens ...... 169 Gravity Deckers ...... 170 DSM Screens ...... 172 Hydrasieves ...... 173 Intemediate-Consistency Washers ...... 173 Inclined Screw Extractor ...... 173 Vacuum Filter ...... 176 VarioSplit ...... 176 Double-Nip Thickener ...... 176 High-Consistency Thickeners ...... 177 Screwpress ...... 177 Economic Comparison of Washing Devices ...... 178 Comparison of Washing and Froth Flotation ...... 179 Bibliography ...... 183 Literature Cited ...... 183

Chapter 17 Conditioning of Secondary Fibers I 185 by Blll Carty Introduction ...... 185 Differences Between Secondary and Virgin Fibers ...... 185 General Aspects of Refining ...... 185 Purpose of Refining ...... 185 Refining Mills ...... 185 Wood Fiber Structure ...... 186 The Refining Process ...... 186 Refining Action ...... 186 Refining Intensity and Refining Power ...... 187

xiv Refining Consistency ...... 188 Other Considerations ...... 188 Double-Disk Refiner ...... 188 StockFlow ...... 189 Refiner Plates ...... 189 Secondary-Fiber Refining ...... 190 OCC for Board Grades ...... 190 Other Considerations for OCC ...... 191 Fractionation and Refining ...... 191 High-Consistency Refining ...... 191 Deinked Ledger Grades for White Paper ...... 192 Deinked Newsprint for Newsprint ...... 193 Refiner Piping Arrangement ...... 193 Typical Refiner Installation ...... 194 Series Arrangement ...... 194 ParaUelArrangement ...... 194 Deflaking ...... 194 Conclusion ...... 195 Bibliography ...... 195 k

I Chapter 18 Dispersion of Contaminants in Recovered Paper Stock I 197 by A. C. Alexander. Roll Kum. and Donald H. McBrlde Introduction ...... 197 The Process of Dispersion ...... 197 Development of Dispersion Systems ...... 197 Dispersing Factors ...... 198 Heat-Softening of Contaminants ...... 198 Contaminant Size Reduction and Mixing ...... 198 I The Blow Valve ...... 198 Disk Refiner ...... 198 Kneading Machines ...... 198 The Dispersion System ...... 199 Thickening Stage ...... 200 Heating Zone ...... 202 Dispersion ...... 202 Kneading-Type Dispersers ...... 202 The Future of Dispersion Systems ...... 202 Case Studies ...... 204 The Effects of Dispersion on Flotation for Ledger Furnishes ...... 204 Cold Dispersion Increases Deinking Efficiency at Japanese Tissue Mills ...... 204 Fullher Japanese Mill Experience ...... 205 Deinking of ONP for Newsprint Production ...... 206 Placement of Kneading Equipment ...... 206 Bibliography ...... 206 Chapter 19 Fractionatlori of Fibrous Stocks: Fundamentals. Process Development. Practical Application 1 207 by W. Musselmann lntroduction ...... 207 Fractionatioeh Effective Approach Toward Limiting the Variant Physical Properties of Raw Materials and Controlling Their Quality ...... 207 Theoretical Considerations of Fractionation Technology ...... 207 Example 1-Fractionation and Joint Processing ...... 209 Example 2-Fractionation and Separate Processing ...... 210 Theoretical Considerations and Laboratory Tests for Limiting Recovered Paper Physical Properties ....211 Demands on a Fractionation System ...... 212 Variables Influencing the Fractionation Effect ...... 212 Terminology ...... 212 Machine Parameters ...... 212 Process Variables ...... 214 Example 1-Fractionation of Department Store Waste ...... 214 Example 2-Fractionation of Sorted Mixed Recovered Paper ...... 214 Preparation of Fractions ...... 216 LF and SF Characteristics ...... 216 LF Fraction Preparation ...... 216 LF Strength Development and Energy Consumption ...... 216 SF Fraction Preparation ...... 217 Energy Use of Separate Refining Compared with Full-Stream Refining ...... 217 Range of LF and SF Fraction Applications ...... 218 Practical Examples ...... 218 Possible Configurations ...... 219 SlushingScreening-Fractionatiodeparate Refining and DispenioeSeparate Processing . 219 Slushing-Prescreening-Fractionatio&eprate Refining-Joint Processing ...... 225 Slushing-PrescreeningSeparate Refining and Dispersion-Joint Processing ...... 225 Control and Regulation ...... 225 Outlook ...... 226 Conclusion ...... 226 Bibliography ...... 227

Chapter 20 Bleaching of Secondary Fiber I 229 by Jeffrey E. Angulo introduction ...... 229 Bleaching Deinked Newsprint ...... 229 Avoid Alkali Darkening ...... 230 Two-Stage Bleaching ...... 231 Bleaching of Chemical Pulps ...... 232 Iis.ueDowe1. Printing and Writing. and Market Pulps ...... 232 Low ChlorineRlypochlorite Bleaching ...... 232 Nonchlorine Bleaching ...... 236 Bleaching of Postconsumer Office Wastes ...... 237 Bibliography ...... 237

xvi Chapter 21

6 Process Water Clarification 1 239 by bwls n. Mshony Introduction ...... 239 Water Recovery for Recycling ...... 239 Heat Conservation ...... 240 Fiber and Ash Recovery ...... 241 Chemical Recovery ...... 241 Paper-Machine White Water Clarification ...... 242 Effluent Treatment ...... 242 Primary Effluent Clarification ...... 242 Secondary Effluent Clarification ...... 242 ! Tertiary Effluent Treatment ...... 242 Equipment ...... 242 Chemical Requirements ...... 243 Process Reviews ...... 243 Economic Return from Recycling Water in a Board Mill ...... 243 Zero-Effluent Water System at a Mill Producing Linerboard and Corrugating Medium ...... 244 Washing Loop in a 'lissue Mill Using Deinked Fiber ...... 246 Secondary Effluent Clarification ...... 246 ? Conclusion ...... 247 ! Bibliography ...... 247

Chapter 22 Rejects Handling and Sludge Pressing in Recycling and Deinking Systems 1 249 by Don McBride introduction ...... 249 RejectsHandling ...... 249 Contaminants vs. Rejects ...... 249 Types of Contaminants ...... 249 Sources of Rejects ...... 250 Rejects Conveying ...... 250 Wires 250 Rejects Dewatering ...... 251 Inclined Screw Thickeners ...... 251 Reciprocating Piston Presses ...... 251 Dewatering Gritty Rejects ...... 252 Sediment Separators ...... 252 Configuration of Rejects-Handling Equipment in a Deinking Facility ...... 252 . Sludge Pressing ...... 252 Dewatering Parameters ...... 253 Sludge Composition ...... 254 Equipment Review ...... 254 Plate and Frame Press ...... 254 Centrifuge ...... 255 Vacuum Filter ...... 256 V-Belt Press ...... 256 Belt Filter Press ...... 256 Screw Press ...... 257 Sludge-Thickening Process Flow ...... 258 What Lies in the Future for Sludge Dewatering? ...... 258 Disposal Alternatives and Equipment Selection ...... 258 Conclusion ...... 259 Blbllography...... 259

Chapter 23 Flowsheet Considerations / 261 by llmothy K. Eatee and Richard J. Spangenberg Introduction ...... 261 Process Parameters that Influence the Design of Flowsheets ...... 261 ExampIes of Flowsheets ...... 262 Very Simple System ...... 262 Crude CIcaning ...... 262 OCCSyslem ...... 264 Systems for Deinking Newsprint and Magazine Papers ...... 264 Deinking of Printing and Writing Grades ...... 266 Conclusion ...... 268

Table of Contents